/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.db.mpp.transformation.dag.util;

import org.apache.commons.lang3.Validate;
import org.apache.iotdb.db.exception.query.QueryProcessException;
import org.apache.iotdb.db.mpp.plan.expression.leaf.ConstantOperand;
import org.apache.iotdb.db.mpp.transformation.datastructure.tv.ElasticSerializableTVList;
import org.apache.iotdb.db.mpp.transformation.datastructure.util.ValueRecorder;
import org.apache.iotdb.db.utils.CommonUtils;
import org.apache.iotdb.tsfile.exception.write.UnSupportedDataTypeException;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.read.common.block.column.*;
import org.apache.iotdb.tsfile.utils.Binary;

import java.io.IOException;
import java.util.Objects;
import java.util.Optional;

public class TransformUtils {

    public static int compare(CharSequence cs1, CharSequence cs2) {
        if (Objects.requireNonNull(cs1) == Objects.requireNonNull(cs2)) {
            return 0;
        }

        if (cs1.getClass() == cs2.getClass() && cs1 instanceof Comparable) {
            return ((Comparable<Object>) cs1).compareTo(cs2);
        }

        for (int i = 0, len = Math.min(cs1.length(), cs2.length()); i < len; i++) {
            char a = cs1.charAt(i);
            char b = cs2.charAt(i);
            if (a != b) {
                return a - b;
            }
        }

        return cs1.length() - cs2.length();
    }

    public static Column transformConstantOperandToColumn(ConstantOperand constantOperand) {
        Validate.notNull(constantOperand);

        try {
            Object value =
                    CommonUtils.parseValue(constantOperand.getDataType(), constantOperand.getValueString());
            if (value == null) {
                throw new UnsupportedOperationException(
                        "Invalid constant operand: " + constantOperand.getExpressionString());
            }

            switch (constantOperand.getDataType()) {
                case INT32:
                    return new IntColumn(1, Optional.of(new boolean[]{false}), new int[]{(int) value});
                case INT64:
                    return new LongColumn(1, Optional.of(new boolean[]{false}), new long[]{(long) value});
                case FLOAT:
                    return new FloatColumn(
                            1, Optional.of(new boolean[]{false}), new float[]{(float) value});
                case DOUBLE:
                    return new DoubleColumn(
                            1, Optional.of(new boolean[]{false}), new double[]{(double) value});
                case TEXT:
                    return new BinaryColumn(
                            1, Optional.of(new boolean[]{false}), new Binary[]{(Binary) value});
                case BOOLEAN:
                    return new BooleanColumn(
                            1, Optional.of(new boolean[]{false}), new boolean[]{(boolean) value});
                default:
                    throw new UnSupportedDataTypeException(
                            "Unsupported type: " + constantOperand.getDataType());
            }
        } catch (QueryProcessException e) {
            throw new UnsupportedOperationException(e);
        }
    }

    public static boolean splitWindowForStateWindow(
            TSDataType dataType,
            ValueRecorder valueRecorder,
            double delta,
            ElasticSerializableTVList tvList)
            throws IOException {
        boolean res;
        switch (dataType) {
            case INT32: {
                if (!valueRecorder.hasRecorded()) {
                    valueRecorder.recordInt(tvList.getInt(tvList.size() - 2));
                    valueRecorder.setRecorded(true);
                }
                res = Math.abs(tvList.getInt(tvList.size() - 1) - valueRecorder.getInt()) > delta;
                if (res) {
                    valueRecorder.recordInt(tvList.getInt(tvList.size() - 1));
                }
                break;
            }
            case INT64: {
                if (!valueRecorder.hasRecorded()) {
                    valueRecorder.recordLong(tvList.getLong(tvList.size() - 2));
                    valueRecorder.setRecorded(true);
                }
                res = Math.abs(tvList.getLong(tvList.size() - 1) - valueRecorder.getLong()) > delta;
                if (res) {
                    valueRecorder.recordLong(tvList.getLong(tvList.size() - 1));
                }
                break;
            }
            case FLOAT: {
                if (!valueRecorder.hasRecorded()) {
                    valueRecorder.recordFloat(tvList.getFloat(tvList.size() - 2));
                    valueRecorder.setRecorded(true);
                }
                res = Math.abs(tvList.getFloat(tvList.size() - 1) - valueRecorder.getFloat()) > delta;
                if (res) {
                    valueRecorder.recordFloat(tvList.getFloat(tvList.size() - 1));
                }
                break;
            }
            case DOUBLE: {
                if (!valueRecorder.hasRecorded()) {
                    valueRecorder.recordDouble(tvList.getDouble(tvList.size() - 2));
                    valueRecorder.setRecorded(true);
                }
                res = Math.abs(tvList.getDouble(tvList.size() - 1) - valueRecorder.getDouble()) > delta;
                if (res) {
                    valueRecorder.recordDouble(tvList.getDouble(tvList.size() - 1));
                }
                break;
            }
            case BOOLEAN: {
                if (!valueRecorder.hasRecorded()) {
                    valueRecorder.recordBoolean(tvList.getBoolean(tvList.size() - 2));
                    valueRecorder.setRecorded(true);
                }
                res = tvList.getBoolean(tvList.size() - 1) != valueRecorder.getBoolean();
                if (res) {
                    valueRecorder.recordBoolean(tvList.getBoolean(tvList.size() - 1));
                }
                break;
            }
            case TEXT: {
                if (!valueRecorder.hasRecorded()) {
                    valueRecorder.recordString(tvList.getString(tvList.size() - 2));
                    valueRecorder.setRecorded(true);
                }
                res = !tvList.getString(tvList.size() - 1).equals(valueRecorder.getString());
                if (res) {
                    valueRecorder.recordString(tvList.getString(tvList.size() - 1));
                }
                break;
            }
            default:
                throw new RuntimeException("The data type of the state window strategy is not valid.");
        }
        return res;
    }
}
